A leaked initial draft majority opinion on Tuesday suggests the US Supreme Court will overturn the Roe v Wade decision that legalised abortion nationwide.
The unprecedented leak — which could have far-reaching effects ahead of US midterm elections in November — has left many in Washington shocked.
But what was the Roe v Wade decision and why was it important?
What is the Roe v Wade decision?
In Roe v Wade, a 1973 ruling by the US Supreme Court — the country’s highest court — stated access to abortion is a constitutional right.
The decision stated the US Constitution protects a pregnant woman's liberty to choose to have an abortion without excessive government restriction, superseding many federal and state abortion laws.
In 1970, Norma McCorvey — also known by the pseudonym Jane Roe — filed a lawsuit against Dallas County district attorney Henry Wade to challenge a Texas law making abortion illegal except by a doctor’s orders to save a woman’s life.
Ms Roe alleged the state laws were unconstitutionally vague and abridged her right of personal privacy, protected by the First, Fourth, Fifth, Ninth, and 14th Amendments.
In a 1992 ruling, Planned Parenthood v Casey, the court guaranteed a woman's right to an abortion until the foetus is viable outside the womb, which is typically at about 22 weeks to 24 weeks of gestation.
Why do people expect the ruling to be overturned?
The draft opinion written by Justice Samuel Alito has been circulating inside the conservative-dominated court since February, news outlet Politico said.
The leak of a draft opinion, while a case is still pending, is an extraordinary breach.
The 98-page draft majority opinion calls the Roe v Wade decision enshrining the right to abortion "egregiously wrong from the start".
"We hold that Roe and Casey must be overruled," Mr Alito wrote in the document, labelled as the "Opinion of the Court" and published on Politico's website.
"It is time to heed the Constitution and return the issue of abortion to the people's elected representatives.
"Abortion presents a profound moral question. The Constitution does not prohibit the citizens of each state from regulating or prohibiting abortion.
"The inescapable conclusion is that a right to an abortion is not deeply rooted in the Nation's history and traditions."
A phone poll of 1,001 US adults was conducted by The Washington Post and ABC News in November 2021, with 60 per cent of those answered saying the ruling should be upheld and 27 per cent saying it should be overturned.
How have US politicians reacted to the leak?
Reproductive rights have been under threat in the US in recent months as Republican-led states move to tighten restrictions, with some seeking to ban all abortions after six weeks, before many women even know they are pregnant.
Senior Democrats denounced the court's apparent move to overturn abortion rights.
"If the report is accurate, the Supreme Court is poised to inflict the greatest restriction of rights in the past fifty years – not just on women but on all Americans," House Speaker Nancy Pelosi and Senate majority leader Chuck Schumer said in a joint statement.
Independent Senator Bernie Sanders said on Twitter: "Congress must pass legislation that codifies Roe v. Wade as the law of the land in this country NOW. And if there aren’t 60 votes in the Senate to do it, and there are not, we must end the filibuster to pass it with 50 votes."
And former US secretary of state Hillary Clinton said: "This decision is a direct assault on the dignity, rights, & lives of women, not to mention decades of settled law. It will kill and subjugate women even as a vast majority of Americans think abortion should be legal. What an utter disgrace."
Protests took place outside the US Supreme Court after the leak.
Why is the leak a big deal?
Leaks of Supreme Court outcomes are extremely rare.
AP reported the publication of an apparent draft running nearly 100 pages was without an evident modern parallel. A decision in the case had been expected before the court begins its summer recess in late June or early July, so it could be more than a month before the court actually issues a final opinion.
If the court does what the draft suggests, the ruling would upend a nearly 50-year-old decision. Its advance publication would also disturb an almost unbroken tradition of secrecy at the court.
The document posted by Politico said the court’s opinion is delivered by Mr Alito. It said the draft was distributed to other members of the court in February.
Neither the Supreme Court or the White House has so far commented.
Lawyers and others who watch the court closely were shocked. Neal Katyal, who has argued dozens of cases before the court and as a young lawyer worked for Justice Stephen Breyer, compared the apparent leak to The New York Times’ 1971 publication of the government’s secret history of the Vietnam War, known as the Pentagon Papers.
“This is the equivalent of the pentagon papers leak, but at the Supreme Court. I’m pretty sure there has never ever been such a leak. And certainly not in the years I’ve been following the Supreme Court,” he wrote on Twitter.
Agencies contributed to this report